type attributes can not be optional, required, or required for purchase

product/admin.py

@@ -2,6 +2,7 @@ from product.models import AttributeType
 from product.models import Type
 from product.models import Item
 from product.models import Attribute
+from product.models import AttributeTypeMembership
 from django.contrib import admin
 
 class AttributeInline(admin.TabularInline):
@@ -13,6 +14,7 @@ class ItemAdmin(admin.ModelAdmin):
 
 
 admin.site.register(AttributeType)
+admin.site.register(AttributeTypeMembership)
 admin.site.register(Type)
 admin.site.register(Item, ItemAdmin)
 admin.site.register(Attribute)

product/migrations/0004_auto__del_atrributetypemembership__add_attributetypemembership.py

@@ -0,0 +1,83 @@
+# encoding: utf-8
+import datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+class Migration(SchemaMigration):
+    
+    def forwards(self, orm):
+        
+        # Deleting model 'AtrributeTypeMembership'
+        db.delete_table('product_atrributetypemembership')
+
+        # Adding model 'AttributeTypeMembership'
+        db.create_table('product_attributetypemembership', (
+            ('attribute_Type', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['product.AttributeType'])),
+            ('type', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['product.Type'])),
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('relation_type', self.gf('django.db.models.fields.CharField')(default='optional', max_length=16)),
+        ))
+        db.send_create_signal('product', ['AttributeTypeMembership'])
+    
+    
+    def backwards(self, orm):
+        
+        # Adding model 'AtrributeTypeMembership'
+        db.create_table('product_atrributetypemembership', (
+            ('attribute_Type', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['product.AttributeType'])),
+            ('type', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['product.Type'])),
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('relation_type', self.gf('django.db.models.fields.CharField')(default='optional', max_length=16)),
+        ))
+        db.send_create_signal('product', ['AtrributeTypeMembership'])
+
+        # Deleting model 'AttributeTypeMembership'
+        db.delete_table('product_attributetypemembership')
+    
+    
+    models = {
+        'product.attribute': {
+            'Meta': {'object_name': 'Attribute'},
+            'attribute_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['product.AttributeType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'product': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['product.Item']"}),
+            'value': ('django.db.models.fields.CharField', [], {'max_length': '256'})
+        },
+        'product.attributetype': {
+            'Meta': {'object_name': 'AttributeType'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '128'})
+        },
+        'product.attributetypemembership': {
+            'Meta': {'object_name': 'AttributeTypeMembership'},
+            'attribute_Type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['product.AttributeType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'relation_type': ('django.db.models.fields.CharField', [], {'default': "'optional'", 'max_length': '16'}),
+            'type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['product.Type']"})
+        },
+        'product.item': {
+            'Meta': {'object_name': 'Item'},
+            'date_available': ('django.db.models.fields.DateField', [], {}),
+            'date_created': ('django.db.models.fields.DateTimeField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'partner_id': ('django.db.models.fields.CharField', [], {'max_length': '32'}),
+            'type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['product.Type']"})
+        },
+        'product.stockrecord': {
+            'Meta': {'object_name': 'StockRecord'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'price_excl_tax': ('django.db.models.fields.FloatField', [], {}),
+            'product': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['product.Item']"}),
+            'tax': ('django.db.models.fields.FloatField', [], {})
+        },
+        'product.type': {
+            'Meta': {'object_name': 'Type'},
+            'attribute_types': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['product.AttributeType']", 'through': "orm['product.AttributeTypeMembership']", 'symmetrical': 'False'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '128'})
+        }
+    }
+    
+    complete_apps = ['product']

product/models.py

@@ -11,12 +11,12 @@ class AttributeType(models.Model):
 class Type(models.Model):
     """Defines a product type"""
     name = models.CharField(max_length = 128)
-    attribute_types = models.ManyToManyField('product.AttributeType', through = 'product.AtrributeTypeMembership')
+    attribute_types = models.ManyToManyField('product.AttributeType', through = 'product.AttributeTypeMembership')
 
     def __unicode__(self):
         return self.name
 
-class AtrributeTypeMembership(models.Model):
+class AttributeTypeMembership(models.Model):
     RELATIONSHIP_CHOICES = (
         ('optional', 'optional'),
         ('required', 'required'),
@@ -48,11 +48,12 @@ class Item(models.Model):
             A boolean if the product is valid
         """
         required_attribute_names = []
-        for attribute_type in self.type.attribute_types.all():
+        for attribute_type in self.type.attribute_types.filter(attributetypemembership__relation_type = 'required'):
             required_attribute_names.append(attribute_type.name)
 
         for attribute in self.attribute_set.all():
-            required_attribute_names.remove(attribute.attribute_type.name)
+            if attribute.attribute_type.name in required_attribute_names:
+                required_attribute_names.remove(attribute.attribute_type.name)
 
         return 0 == len(required_attribute_names)